Renal artery stenosis due to neurofibromatosis type 1: case report and literature review

BACKGROUND: Neurofibromatosis type 1 (NF1) is a relatively common autosomal dominant disorder. The most common vascular abnormality in patients with NF1 is bilateral or unilateral renal artery stenosis. CASE REPORT: A 16-year-old boy presented with a headache of 4-year duration and was found to be moderately hypertensive. On physical examination, axillary freckling and multiple café-au-lait spots were revealed over the trunk, while numerous small nodules were palpable on the limbs. Biopsy of subcutaneous nodule showed neurofibroma. Lisch nodules were identified on slit-lamp examination and grade I hypertensive retinopathy was present on fundoscopy. Clinical laboratory investigations revealed that renal and liver function tests, blood cells count, urinalysis, serum electrolytes, serum levels of renin and aldosterone, and 24-hour urine levels of catecholamines were all within normal ranges. Abdominal ultrasound and CT were normal. Both kidneys were of normal size. CT angiography showed right renal artery stenosis (>90%) at the ostium. The final diagnosis of NF1 with right renal artery stenosis and secondary hypertension was then made. The patient was treated with Procardin (30 mg/d) and improved with a significant decline in blood pressure. The main outcomes were to control blood pressure without necessarily proceeding with PTRA. We also present a review of the literature. CONCLUSIONS: NF1 may present with hypertension due to renal artery stenosis in children. All young patients (<30 year) with hypertension should be clinically screened for secondary causes of hypertension, including NF1, so that renal revascularization can be offered before permanent end organ damage has occurred. First-line management using medication alone could be appropriate, keeping the interventional options for when the patient's condition deteriorates.